@startuml HDF
    participant TD                  as TD
    participant SW                  as SW
    participant UI                  as UI
    actor       USER                as US

    'Possible actions and interaction types
    ' External on CANBus
    ' TD -> SW: MSG: Message
    ' SW -> TD: MSG: Message

    ' Internal to the application
    ' XX -> YY: CMD: Command
    ' XX -> XX: ACT: Action

    ' External on OS/FS
    ' SW -> Script: ACT: Command
    ' Script -> OS: CMD: Command
    ' Script -> SW: MSG: Message
    ' OS -> Script: MSG: Message

    ' US -> UI: User actions are:
    '   ASK: Display a <message>
    '   ENT: User enters a value or string
    '   TCH: User touches a button (RadioButton, CheckBox, ...)
    '   SCL: User scrolls a flip-able area


  == Main TX HDF ==
    UI ->o UI: ⟲: Main Treatment Screen
    US -> UI: TCH: HDF Menu Option
    UI -> US: ACT: Display HDF Screen   \
                    \n\t  - Pressures   \
                    \n\t  - Pressures Graph \
                    \n\t  - HDF
    group Pressures Data
        TD --> UI: ...
    end
    UI -> US: ACT: Show Pressures Data BroadCast
    group Plot Timer (1 min)
        UI --> UI: ...
    end
    UI -> SW: ACT: Request HDF Data
    SW -> TD: ACT: Request HDF Data
    TD -> SW: ACT: Response HDF Data
    SW -> UI: ACT: Response HDF Data
    UI -> US: ACT: Display HDF Data

 == Pressures Data ==
    TD -> SW: MSG: [x24: #12] \nTD Pressures Data\n(F32) artPress, \n(F32) venPres\n(U32) limitState\n(S32) artMin\n(S32) artMax\n(S32) venMin\n(s32) venMax\n(F32) artLong\n(U32) venLong\n(F32) tmpPress\n(F32) tmpMin\n(F32) tmpMax 
    SW -> UI: CMD: Update TD Pressures\n(F32) artPress, \n(F32) venPres\n(U32) limitState\n(S32) artMin\n(S32) artMax\n(S32) venMin\n(s32) venMax\n(F32) artLong\n(U32) venLong\n(F32) tmpPress\n(F32) tmpMin\n(F32) tmpMax 
@enduml